Epithelia Flashcards
Breast cancer cause?
abnormal proliferation of epithelial cells
Cystic fibrosis cause?
defective epithelial chloride ion transport
Cholera cause?
enhanced activation of epithelial chloride ion transport in GI tract
Atherosclerosis cause?
(plaque build up in arteries)
superficial injury to epithelial lining of blood vessels causes cardiovascular disease
Epithelia characteristics?
- tight junctions
- separated from underlying tissues by basement membrane BM - connective layer
- cells undergo rapid division to replace damage cells - (opportunity for tumours)
Shapes of epithelial cells?
- columnar - taller than wide
- cuboidal - cube
- squamous - sheets of flattened cells
Number of layers of cells?
- simple - one layer - diffusion, absorption secretion
- stratified - multiple layers - basal, apical layers - protection
(thiner - better diffusion, thicker - better protection)
Transitional epithelia?
can stretch, distend, change shape
- bladder
Blood vessel epithelia?
simple squamous
Kidney tubule epithelia?
simple cuboidal
GI tract epithelia?
simple columnar
Skin epithelia?
stratified squamous
Reproductive system epithelia?
stratified cuboidal
Respiratory epithelia?
pseudo stratified columnar - one layer looks like two
Bladder epithelia?
transitional
Exchange epithelia?
- one layer
- flattened cell shape
- pores
- lung, blood vessels
Transporting epithelia?
- one layer
- cuboidal or columnar
- tight junctions - limit movement
- intestine, kidney
Ciliated epithelia?
- one layer
- cuboidal or columnar
- cilia move fluid across surface
- trachea, female reproductive tract
Protective epithelia?
- many layers
- flattened surface, polygonal in deeper layers
- cells connected by many desmosomes
- exocrine (pancreas and salivary) and endocrine (thyroid)
Secretory epithelia?
- one up to many layers
- columnar to polygonal
- extensive rough ER (proteins) or smooth ER (steroids)
Cilia function?
movement
Microviliia function?
increase surface area for absorption
Simple squamous?
- single layered flattened cells
- ventral nucleus
- thin cells
- irregular shape
- no gaps between cells
- lining of body cavities - mesothelium, lining of blood vessels - endothelium
What lines the body cavities?
mesothelium
- includes pericardium
What lines blood vessels?
endothelium
Small intestine lining modifications?
simple columnar epithelium
> increase surface area for absorption
- large folds
- (microscopic) villi - covered by epithelium
- microvilli on apical surface of epithelial cells (electron microscope)
> mucus secretion to lubricate gut contents
- microvilli form brush border mucus adheres to
- goblet cells secrete mucus
- BM spereates epithelial cells from underlying tissue
Respiratory epithelium modifications?
pseudo stratified ciliated columnar
- columnar cells
- basal cells
- goblet cells
Oesophagus epithelium modifications?
stratified squamous
- desquamation - flattened cells shed from surface
- basal cells divide and move up
- protects underlying tissues from abrasion
Thin skin epithelium modifications?
stratified squamous keratinised
- rejects water loss - keratin
Bladder epithelium modifications?
transitional
- high numbers of tight junctions prevent leakage of urine fro bladders into tissues
Functional difference between non-epithelial and epithelial cells?
highness of junctions between them
